Systems and Methods for Percutaneous Division of Fibrous Structures

ABSTRACT

A device for dividing a fibrous structure comprising a catheter; an expandable member positioned near a distal end of the catheter and in fluid communication with a lumen of the catheter; and a cutting element situated on an outer surface of the expandable member. A method for dividing a fibrous structure comprising positioning, proximate the fibrous structure, an expandable member having a cutting element situated thereon; expanding the expandable member outwards to tension the fibrous structure across the cutting element; and activating the cutting element to weaken or cut the fibrous structure. A method for treating carpal tunnel syndrome comprising inserting a needle into the carpal tunnel; directing a guidewire to a position proximate the transverse carpal ligament; advancing, along the guidewire, a device having an expandable member and a cutting element; positioning the cutting element; tensioning the ligament across the cutting element; and weakening or cutting the ligament.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Divisional Application of U.S. patent applicationSer. No. 14/958,003, filed Dec. 3, 2015, which claims priority to U.S.Provisional Application Ser. No. 62/086,950, filed Dec. 3, 2014, thedisclosure of each of which is hereby incorporated herein by referencein their entireties.

BACKGROUND

The body contains a variety of anatomic compartments with one or morefibrous walls. In certain pathologic situations, the structures withinthe compartment can be compressed either by swelling or inflammation ofthe structures or constriction by the compartment walls. For example,compression of blood vessels or nerves passing through the compartmentcan lead to poor blood flow or loss of neurologic (sensory or motor)function in the tissues within or beyond the compartment. Examples ofsuch conditions include carpal tunnel syndrome, plantar fasciitis,fascial compartment syndrome and abdominal compartment syndrome. Thetreatment of these conditions will often involve cutting one or morefibrous walls to release pressure on the compartment's anatomicstructures. This usually requires open surgery either with direct orendoscopic vision. Few if any percutaneous options exist for theseconditions.

Carpal tunnel syndrome (CTS) is the most common cumulative traumadisorder (CTD's) which collectively account for over half of alloccupational injuries. It exacts a major economic burden on societyincluding billions in lost wages and productivity. The carpal tunnel islocated in the wrist. It's bounded by the carpal bones posteriorly,laterally and medially and by the transverse carpal ligament anteriorly.The flexor tendons and the median nerve pass through the carpal tunnel.Cumulative trauma leads to inflammation within tunnel and manifestsitself clinically through its compressive effect on the median nerveresulting it motor and sensory dysfunction in the hand. The diagnosis isusually confirmed with nerve conduction tests. Traditional surgicalapproaches are effective but invasive and have to be performed in asurgical operating room. An incision is made in the palm or over thewrist. The transverse carpal ligament is surgically exposed and dividedwith scissors or a scalpel. Endoscopic approaches are less invasive butmore technically challenging, have been associated with a highercomplication rate and are more expensive. They still require a 1 cmsurgical incision and some initial surgical dissection before theendoscope is passed into the carpal tunnel. One device attempts to use atransillumination to guide blind passage of a protected knife. Anotherdevice passes a saw-like cutting device into the carpal tunnel blindlyor by ultrasound guidance.

It is therefore desirable to have a percutaneous approach to treatcarpal tunnel syndrome that is less invasive than existing approachesand that results in less trauma and quicker recovery times for thepatient.

SUMMARY

The present disclosure is directed to a device for dividing a fibrousstructure. The device may comprise a catheter having a proximal end, adistal end, and lumen extending therebetween; an expandable memberpositioned near the distal end of the catheter and in fluidcommunication with the lumen of the catheter; and a cutting elementsituated on an outer surface of the expandable member.

In various embodiments, the expandable member may be configured tocontact the fibrous structure and expand outwards to tension the fibrousstructure across the cutting element. The expandable member, in variousembodiments, may include a balloon.

The cutting element, in various embodiments, may be configured to applya mechanical force to weaken or cut the fibrous tissue. Additionally oralternatively, the cutting element, in various embodiments, may beconfigured to emit electrical or thermal energy to weaken or cut thefibrous tissue. The cutting element may include a blade and/or anelectrocautery lead in some embodiments.

The device, in various embodiments, may further comprise at least onesensing element and/or stimulating element on the outer surface of theexpandable member. The sensing and/or stimulating elements may beconfigured to detect or stimulate neuroelectrical in a nearby nerve tofacilitate at least one of positioning and orienting the device alongthe fibrous structure.

The device, in various embodiments, may still further comprise one ormore lighting elements situated along a length of the expandable memberproximate the cutting element. A brightness and a wavelength of lightemitted by the one or more lighting elements may be configured such thatthe light is visible through subcutaneous tissues and skin, and notvisible or visible at significantly lower brightness) through thefibrous wall.

In another aspect, the present disclosure is directed to a method fordividing a fibrous structure. The method may comprise positioning,proximate the fibrous structure, an expandable member having a cuttingelement situated thereon; expanding the expandable member outwards totension the fibrous structure across the cutting element; and activatingthe cutting element to weaken or cut the fibrous structure.

The method, in various embodiments, may further comprise determiningwhether a nerve is present in the vicinity of the cutting element. Thismay include at least one of monitoring feedback from the at least oneelement for signals associated with neurological activity; and emitting,via the at least one element, a signal suitable for stimulatingneuroelectrical activity. Determining whether a nerve is present can, invarious embodiments, be used to adjust a position and/or orientation ofthe cutting element.

In yet another aspect, the present disclosure is directed to a methodfor treating carpal tunnel syndrome. The method may comprise inserting aneedle into the carpal tunnel; directing a guidewire through the needleto a position proximate the transverse carpal ligament; advancing, alongthe guidewire, a device having an expandable member and a cuttingelement; positioning the cutting element along a portion of thetransverse carpal ligament to be divided; expanding the expandablemember outwards to tension the transverse carpal ligament across thecutting element; and activating the cutting element to weaken or cut thetransverse carpal ligament.

The guidewire, in an embodiment, may be further advanced through theskin and out of the body to provide excellent column strength tofacilitate advancement of the device. Ultrasonic imaging and/orillumination, in various embodiments, may be used to facilitate one ormore of the steps the method.

DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a schematic view of an anatomical compartment of thehuman body;

FIG. 2 depicts a device for percutaneous division of fibrous structures,in accordance with an embodiment of the present disclosure;

FIGS. 3A and 3B depict side and cross-sectional views of a device forpercutaneous division of fibrous structures in deflated and inflatedstates, in accordance with an embodiment of the present disclosure;

FIG. 4A depicts a schematic view of the device of FIGS. 3A and 3B in aninflated state for tensioning a fibrous wall of an anatomicalcompartment;

FIGS. 4B ₁-4B₅ depict schematic views of various potentialcross-sectional shapes of a balloon, in accordance with an embodiment ofthe present disclosure;

FIGS. 5A and 5B depict a mechanical cutting element of a device forpercutaneous division of fibrous structures, in accordance with anembodiment of the present disclosure;

FIGS. 6A-6C depict electrical/thermal cutting elements of a device forpercutaneous division of fibrous structures, in accordance with anembodiment of the present disclosure;

FIGS. 7A-7C depict elements for sensing neuroelectrical activity,stimulating neuroelectrical activity, or both, in a nearby nerve, ifpresent of a device for percutaneous division of fibrous structures, inaccordance with an embodiment of the present disclosure;

FIG. 7D depicts a perspective view of a device for percutaneous divisionof fibrous structures, in accordance with an embodiment of the presentdisclosure;

FIG. 7E depicts a perspective view of a device for percutaneous divisionof fibrous structures, in accordance with another embodiment of thepresent disclosure;

FIG. 7F depicts top and cross-sectional schematic views of a device forpercutaneous division of fibrous structures, in accordance with anotherembodiment of the present disclosure;

FIGS. 8A-8C depict schematic views of a device for percutaneous divisionof fibrous structures having lighting elements, in accordance with anembodiment of the present disclosure;

FIG. 9A depicts an experimental test in which a device for percutaneousdivision of fibrous structures is used for cutting synthetic tissue, inaccordance with an embodiment of the present disclosure;

FIGS. 9B and 9C depict another experimental test in which a device forpercutaneous division of fibrous structures is used for cutting bovinepericardium tissue, in accordance with an embodiment of the presentdisclosure;

FIGS. 10A and 10B depict side and cross-sectional views of a device forpercutaneous division of fibrous structures in collapsed and expandedstates, in accordance with an embodiment of the present disclosure;

FIGS. 11A-11C depict steps of a method for percutaneous division offibrous structures, in accordance with one embodiment of the presentdisclosure;

FIG. 12A depicts a carpal tunnel and associated anatomical structureswithin the human body;

FIGS. 12B-12F depict steps of a method for treating carpal tunnelsyndrome, in accordance with one embodiment of the present disclosure;

FIG. 13 depicts a kit for use in a method for treating carpal tunnelsyndrome, in accordance with one embodiment of the present disclosure;and

FIGS. 14A-14I depict steps of a method for treating carpal tunnelsyndrome using the kit of FIG. 13, in accordance with one embodiment ofthe present disclosure.

DETAILED DESCRIPTION

The present disclosure is directed to a medical device, and inparticular, devices for percutaneous division of fibrous structures.While the devices and methods described herein may be used forpercutaneous division of any sort of fibrous structure within the body,the present disclosure may, from time to time, refer to the treatment ofcarpal tunnel syndrome as an exemplary application. The carpal tunnel isan anatomic compartment in the wrist bounded by the carpal bones and thetransverse carpal ligament. The clinical symptoms of carpal tunnelsyndrome primarily arise from compression of the median nerve as itpasses through the tunnel. Surgical division of the transverse carpalligament relieves the compression of the median nerve and its associatedsymptoms. Referring to FIG. 1, device 200, in various embodiments, maybe utilized to divide a fibrous wall 110 of an anatomical compartment100 within the body to relieve pressure on anatomical structures 120within compartment 100.

Percutaneous Division Device 200

Referring now to FIG. 2, percutaneous division device 200 of the presentdisclosure may generally include a catheter 300, an expandable member400, one or more cutting elements 500, and one or moresensing/stimulating elements 600. Percutaneous division device 200 maybe inserted into the body and advanced towards an anatomic compartment100, such as the carpal tunnel, requiring treatment. Sensing/stimulatingelement 600 may optionally be utilized to help position device 200within the compartment, and to avoid damaging any nearby nerves. Onceproperly positioned within the anatomic compartment, expandable member400 may be expanded to apply a radial force generating lateral tensionalong a portion of the fibrous wall of the compartment. Cutting element500 may be configured to engage the tensioned portion to divide thefibrous wall and thereby decompress the anatomic compartment fortherapeutic effect.

Referring now to the schematic views of FIGS. 3A and 3B, percutaneousdivision device 200 may include a catheter 300. Catheter 300, in variousembodiments, may be rigid, semi-rigid or flexible. Catheter 300 may bemade of any biocompatible material including plastic or metal. Inembodiment, catheter 300 may be made of a flexible plastic material suchas polyurethane, polyethylene or flourothermoplastic, among othersuitable plastics.

Catheter 300, as shown, may have a proximal end 310, a distal end 320,and an outer surface 330. Catheter 300, in various embodiments, mayinclude at least one lumen 340 through which fluids may be accommodatedand directed between proximal end 310 and distal end 320. Catheter 300may further include one or more openings 332 (shown in FIG. 3A as sideholes) through which fluid may be directed between lumen 340 and anenvironment situated beyond outer surface 330 outside of catheter 300.Openings 332, in an embodiment, may be situated proximate distal end 320so as to provide fluid communication between lumen 340 and an interiorportion 410 of expandable member 400 positioned about a correspondingportion of outer surface 330 of catheter 300, as shown. In operation,fluid may be introduced into fluid lumen 340 at proximal end 310,directed towards distal end 320, and through openings 332 into interiorportion 410 to inflate expandable member 400. Similarly, fluid may bewithdrawn from expandable member 400 along the reverse path to deflateexpandable member 400. Catheter 300, in various embodiments, may furtherinclude at least one lumen 350 for accommodating a guidewire 352 (notshown) for facilitating positioning of catheter 300 within compartment100.

One of ordinary skill in the art will recognize that these are merelyillustrative examples of suitable configurations of catheter 300, andthat the present disclosure is not intended to be limited only to theseillustrative embodiments.

Still referring to FIGS. 3A and 3B, percutaneous division device 200 mayinclude expandable member 400, such as a balloon or similar expandablestructure. For simplicity, expandable member 400 may be referred toherein as balloon 400 in the context of describing percutaneous divisiondevice 200; however, it should be recognized that expandable member 400is not intended to be limited as such. Balloon 400, in an embodiment,may be substantially non-compliant, and can be made of a thin layer or asimilar flexible plastic material.

Balloon 400 may be coupled to catheter 300 in a manner suitable forreceiving and retaining fluid from lumen 340 of catheter 300 withininterior portion 410 of balloon 400. In one such embodiment, balloon 400may be positioned about a portion of outer surface 330 containingopening(s) 332 such that fluid directed through opening(s) 332 entersinterior portion 410 of balloon 400. Balloon 400 may be bonded tocatheter 300 to retain fluid directed into its interior portion 410 toallow for inflating balloon 400 during the surgical procedure.

Referring now to FIG. 4A, balloon 400 may be shaped to apply tension tofibrous wall 110. As balloon 400 is inflated, it pushes outward,generating a force in a radial direction on a portion of wall 110, whichstretches that portion of wall 110 in a lateral direction. In variousembodiments, cutting element 500 may be longitudinally oriented onballoon 400, meaning that the lateral tension created in wall 110 byballoon 400 acts in a direction substantially transverse to thelongitudinally-oriented cutting element 500 situated on the surface ofballoon 400. As configured, lateral tension causes wall 110 to becometaut across cutting element 500, thereby making it easier to divide. Inparticular, as cutting element 500 weakens a contacted portion of wall110, tension applied by balloon 400 facilitates division by pulling wall110 apart along the weakened area. Further, as shown in FIG. 4A,stretching wall 110 taut provides for wall 110 to be contacted by adiscrete portion of cutting element 500 (e.g., the tip of cuttingelement 500, as shown), rather than with a wider portion cutting element500 as may be the case if wall 110 were slack and allowed to conformaround cutting element 500. Stated otherwise, the tension applied byballoon 400 allows cutting element 500 to act with high energy densityon a small portion of wall 110, thereby providing for a cleaner cut withless tissue damage, which in turn may reduce the recovery period for thepatient.

Still referring to FIG. 4A, balloon 400 may be further shaped and sizedto accommodate the specific anatomy of the compartment 100 within whichit will be deployed. This may include, for example, being shaped andsized in a manner suitable for manipulating the position of, orminimizing pressure applied to, anatomical structures 120 situatedwithin compartment 100. This may serve to protect these anatomicalstructures 120 from damage resulting from contact with cutting element500 and/or to dissect tissues within the compartment to create morespace for the anatomic structures within the compartment. As shown inFIG. 4A, in an embodiment, balloon 400 may have an elongatedcross-section (e.g., ovular) which, when positioned against fibrous wall100, provides contact between an elongated side of balloon 400 andfibrous wall 100 that prevents anatomical structures 120 from slidingaround its lateral ends and towards the site of division, where theycould be damaged by cutting element 500. In another embodiment, balloon400 may be provided with a substantially circular cross-section (notshown) with a large enough diameter sufficient to push nearby tendons,nerves or other anatomical structures 120 outward from device 200 wheninflated.

Referring now to FIGS. 4B ₁-4B₅, in other embodiments, balloon 400 maybe provided with a variety of other cross sections. For example, balloon400 may have, without limitation, a substantially circular (FIG. 4B ₁),ovular (FIG. 4B ₂), rectangular (FIG. 4B ₃), or triangular (FIG. 4B ₄)cross sectional shape, to help achieve the desired effect on wall 110and/or anatomical structures 120. Referring to FIG. 4B ₅, in anembodiment, multiple balloons or shaped members may be positioned inrelation to one another to help form the overall shape of balloon 400.Here, one such embodiment illustrates a “pontoon”-like configurationwherein two smaller balloons are positioned on opposing sides of alarger central balloon to help form an overall ovular shape. Of course,one of ordinary skill in the art will recognize any number of additionalconfigurations for this purpose within the scope of the presentdisclosure.

Similarly, balloon 400 may be adapted to minimize contact with (andapplying resulting pressure on) certain surrounding anatomicalstructures 120 within compartment 100. For example, the small verticaldimension of the elongated cross-sectional design of FIG. 4A may serveto minimize pressure exerted on median nerve 122 situated below the siteof division, whilst its longer horizontal cross-sectional dimension maystill serve to apply tension to fibrous wall 100 and push tendons 124aside. Embodiments of balloon 400 may be provided with suitablelongitudinal profiles adapted for similar purposes.

Referring now to FIGS. 5A and 5B, percutaneous division device 200 mayfurther include one or more cutting elements 500 situated on balloon400. The specific orientation of cutting element 500 relative to theaxis of the catheter 300 may depend on the specific anatomy of thecompartment. Cutting element 500, in various embodiments, may include amechanical element 510 such as a sharpened blade, as shown in FIG. 5A.In an embodiment, the mechanical element 510 may be provided with aremovable cover 512 to protect surrounding tissue during positioning ofdevice 200 and exposed just prior to balloon inflation, as shown in FIG.5B. In another embodiment, the mechanical element 510 may be sheathedwithin catheter 300 and advanced once balloon 400 is inflated (notshown). In operation, when balloon 400 is inflated, the mechanicalelement 510 makes contact with the fibrous wall 110. As the pressure inballoon 400 further increases, the axial and radial forces tension thefibrous wall 110, and the radial force pushes mechanical element 510through the fibrous wall 110, thereby dividing fibrous wall 110 andrelieving the pressure in compartment 100, as described in more detaillater in the disclosure.

Referring now to FIGS. 6A-6C, cutting element 500, in various otherembodiments, may include an electrical element 520 configured to utilizeelectrical and/or thermal energy to divide fibrous wall 100. Forexample, cutting element 520 may include a unipolar or bipolar leadsconfigured to communicate electrically with an electrocautery generator,as shown in FIGS. 6A and 6B, respectively. In operation, when balloon400 is inflated and the electrocautery lead(s) is in contact withfibrous wall 110, the electrocautery generator may be activated todeliver radiofrequency energy to the electrocautery lead(s). Theradiofrequency energy heats and cuts the contacted, tensioned portion ofthe fibrous wall 110 and the fibrous wall 110 is divided under thepressure of balloon 400, thereby relieving the pressure in compartment100, as described in more detail later in the disclosure. A bipolarconfiguration may be preferable in anatomic areas with criticalstructures (nerves, blood vessels) in the vicinity, as it limits thethermal spread of the radiofrequency energy. Leads 520 attached toalternative energy sources, such as microwave and laser light, may alsobe applicable in certain applications. As later shown in FIGS. 7E and7F, percutaneous division device 200 may further comprise a layer ofinsulating material 522 situated between cutting element 520 and balloon400, so as to protect balloon 400 from heat-related damage when cuttingelement 500 is energized.

Embodiments of cutting element 520 utilizing electrical and/or thermalenergy for division, in an embodiment, may further have a sharpknife-like edge (not shown) so that fibrous wall 110 is divided usingboth electrical and mechanical means. Similarly, referring FIG. 6C,lead(s) 520 may be provided with a substantially triangularcross-section. As configured, the leading edge 522 of thetriangularly-shaped lead 520 may serve to concentrate the electrical andmechanical, thereby providing highly-concentrated energy density along afine line at the site of division. This may result in less tissuetrauma, shorter cutting times, faster recovery times, and more precisedivision of the fibrous wall 100. Further, the sloping surfaces 524 ofthe triangularly-shaped lead 520 may serve to further spread (i.e.,tension) the portion of fibrous wall 100 proximate leading edge 522,thereby further enhancing the ability of device 200 to cut and dividefibrous wall 110. Further, a portion of the surface of the lead 520extending up sloping surfaces 254 may be coated with an insulatingmaterial, allowing further concentration of the energy density toleading edge 522.

Referring now to FIGS. 7A-7C, percutaneous division device 200 mayfurther include one or more elements 600 configured for sensingneuroelectrical activity, stimulating neuroelectrical activity, or both,in a nearby nerve, if present. Such elements may be utilized todetermine whether balloon 400 and cutting element 500 are positionedappropriately relative to structures within compartment 100.

As shown in FIG. 7A, in an embodiment, element(s) 600 may includesensing element(s) 610 configured to detect nerve conduction. Asconfigured, an operator may utilize feedback from sensing element(s) 610to determine whether cutting element 500 may be in the vicinity of anerve, such as the median nerve in the carpal tunnel. Sensing element610 may be connected to an electrical signal detector. Sensing element610 may be designed to detect an electrical signal emanating from anearby nerve (e.g., the median nerve) at baseline or from activation ofmotor nerve fibers during normal muscle contraction (e.g., hand grip) orduring electrical stimulation of the nerve (e.g., in the forearm),similar to how nerve conduction studies are performed. A positive signalwould confirm that the nerve is located away from cutting element 520.

As shown in FIG. 7B, In another embodiment, element(s) 600 may includestimulating element(s) 620 configured to emit a signal for stimulatingnearby nerves. Simulating element 620 may be configured to function inan analogous manner as commonly utilized nerve stimulators used inanesthesia to assess successful pharmacologic muscle relation. Anelectrical stimulus may be delivered to the nerve by stimulating element620. If stimulating element 620 is in the vicinity of a nerve, acorresponding motor reaction is noted in the muscles supplied by thenerve such as twitching of the hand from stimulation of the mediannerve. A positive response to stimulation would provide confirmationthat the nerve is located away from cutting element 520.

In yet another embodiment (not shown), element(s) 600 may include asensing element(s) 610 and a separate stimulating element(s) 620. Instill another embodiment (not shown), element(s) 600 may include ahybrid element configured for both sensing and stimulating functionality(not shown).

Referring to FIG. 7C, in a further embodiment, element(s) 600 mayinclude an element 630 configured for cutting functionality, and atleast one of sensing and/or stimulating functionality. Stated otherwise,element 630 may be a hybrid element configured to be a cutting element500, and at least one of a sensing element 610 and stimulating element620. Element 630 may initially be utilized as a sensing element 610and/or stimulating element 620 to facilitate positioning as describedabove. Once the operator confirms that the nerve is not in the vicinityof cutting element 500, element 630 can be used as a cutting element 500to mechanically, electrically, or thermally weaken or cut fibrous wall110. Element 630 can be a single lead, where its functionality as asensing, stimulating or cutting element is determined by whether itelectrically communicates with a signal detector, stimulator or cuttingenergy source.

A layer of insulating material, in various embodiments, may be situatedbetween element(s) 600 and balloon 400, so as to protect balloon 400from heat-related damage when element(s) 600 are energized.

Referring to FIG. 7D in an embodiment, percutaneous division device 200may include an expandable member 400 in relation to a catheter 300 witha stimulating element 620 located on the inferior surface of theexpandable member 400 and a cutting element 500 located on the superiorsurface off the expandable member. The cutting element 500 is separatedfrom the expandable member 400 by a layer of insulating material 522which protects the expandable member 400 from damage from heat generatedby the cutting element 500. The cutting element 500 in this embodimentis a bipolar lead with and triangular active lead 526 and a flat passivereturn lead 527,

Referring to FIG. 7E and 7F in an embodiment, percutaneous divisiondevice 200 may include an expandable member 400 in relation to acatheter 300 with a hybrid element 630 located on the superior surfaceof the expandable member 400 The hybrid element 630 is separated fromthe expandable member 400 by a layer of insulating material 522 whichprotects the expandable member 400 from damage from heat generated bythe hybrid element 630. The hybrid element 630 in this embodiment is abipolar lead with and triangular active lead 526 and a flat passivereturn lead 527. In stimulating mode, either or both leads can be usedto deliver a stimulating signal to confirm that the nerve is not in thevicinity of the hybrid element. I cutting mode the bipolar electricalenergy is delivered between the active lead 526 and the return lead 527.

Depending on the positioning of element(s) 600 on balloon 400, and onknown anatomy, the operator may further determine whether device 200 isproperly positioned. For example, in a carpal tunnel surgical procedure,it may be desired to position device 200 between the transverse carpalligament (i.e., fibrous wall 110) and the median nerve (i.e., nerve122), with cutting element 500 (or hybrid element 630) directed towardsthe transverse carpal ligament. If element(s) 600 are positionedproximate cutting element 500 and provide feedback indicating that thenerve is in that vicinity, an operator may deduce that: 1) balloon 400is properly oriented, but improperly positioned under the median nerve,rather than between it and the transverse carpal ligament, or 2) balloon400 is properly positioned, but improperly oriented with cutting edge500 facing the median nerve rather than the transverse carpal ligament.Similarly, in embodiments where element(s) 600 are positioned on anopposing side of balloon 400 from cutting element 500, the operator maymake similar, albeit opposite, deductions. To that end, it should beapparent to one of ordinary skill in the art that any suitable number,combination, and arrangement of element(s) may be utilized for any givenapplication to provide suitable feedback for facilitating placement ofballoon 400 and cutting element 500 within compartment 100, and that thepresent disclosure is not intended to be limited to any such exemplaryembodiments thereof provided herein.

Referring now to FIGS. 8A-8C, as an additional or alternative featurefor facilitating use, percutaneous division device 200 may include oneor more lighting elements 700 along the length of balloon 400 in thevicinity of cutting element 500, as shown in FIGS. 8A-8C. The brightnessand wavelength of the row of lighting elements 700 may be configuredsuch that they can be visualized through the subcutaneous tissues andskin but not visualized (or visualized at significantly and discerniblylower brightness) when place below fibrous wall 110. As such, when theballoon is positioned below fibrous wall 110 and the lighting elements700 are activated, and the length of fibrous wall 110 relative to thelength of cutting element 500 on balloon 400 can be determined byassessing which light elements 700 shine through the tissues. In anembodiment, the row of lighting elements 700 can be longer than thelength of fibrous wall 110 so that lighting elements 701 and 705 at theproximal end and distal end of balloon 400 can shine through to helpdetermine the relative length of the tissue. Once cutting element 500 isactivated, the completeness of the fibrous wall division can beassessed. A complete division would be indicated if all light elements700 shine through. If the division is incomplete, one or of the lightelements 700 will remain dark and the operator can make another attemptto completely divide fibrous wall 110. In addition, should balloon 400and hence cutting element 500 be relatively shorter than the length offibrous wall 110, multiple divisions along the length of fibrous wall110 can be employed. Although disclosed as having a plurality oflighting elements 700 along the length of balloon 400, it should beappreciated that one lighting source 700 extending the length of balloon400 can be used.

Referring now to FIGS. 9A-9C, synthetic and bovine tissues were dividedduring testing with a prototype of an embodiment of percutaneousdivision device 200. The prototype device comprised a 20mm balloon,inflated with water to 5 atm, with polyimide and PEEK film materialsituated between electrodes and the balloon surface to provideinsulation. A bipolar arrangement of electrodes made from coatedflat-wire were spaced 2 mm apart and mounted vertically on theinsulating material to simulate a triangular shaped cutting element.Referring first to FIG. 9A, a strip of SynDaver synthetic tissue wasplaced laterally across the prototype device and tensioned to a levelrepresentative of the transverse carpal ligament of the carpal tunnel. Afull cut through the SynDaver synthetic tissue was produced byenergizing the electrode with 20 W of power. Referring to FIGS. 9B and9C, a second test using similar setup, only with bovine pericardiumtissue, was performed using the prototype device. As shown in FIG. 9C, afull cut through the bovine pericardium tissue was produced with 20 W ofpower.

Percutaneous Division Device 800

FIGS. 10A and 10B illustrate percutaneous division device 800 of thepresent disclosure. Device 800 may generally include similar componentsas device 200, and may additionally or alternatively comprise anexpandable member 900 configured for expanding and contracting viamechanical actuation.

Expandable member 900 may comprise a surface 910 on which cuttingelement 500 and (if equipped) sensing/stimulating elements 600 may besituated as in device 200. In various embodiments, surface 910 may bemade of a flexible material capable of collapsing when device 800 is ina non-actuated state, and expanding when device 800 is in an actuatedstate. In an embodiment, surface 910 may be a balloon or other membraneformed of a flexible material.

Expandable member 900 may further comprise support members 920configured to expand surface 910 when device 800 is in an actuatedstate, and to collapse surface 910 when device 800 is in a non-actuatedstate, similar to the way fluid may be used to inflate and deflateexpandable member 400 of device 200. In various embodiments, supportmembers 920 may include ribs or similar structure configured to pressradially outwards on surface 910 in an expanded state. In an embodiment,support members 920 may be formed of a shaped-material that springsoutwards when a retaining force is released so as to expand surface 910.In another embodiment, support members 920 may be configured to spreadoutwards and collapse inwards under mechanical actuation.

In various embodiments, expandable member 900 may be actuated via amechanism 362 extending through a lumen 360 in catheter 300. Mechanism362, in an embodiment, may include an elongated shaft 364 coupled tosupport members 920. In an embodiment, elongated shaft 364 may beactuated (e.g., pushed or pulled in an axial direction) that causessupport members 920 to spread radially or collapse axially to expand andcollapse expandable member 900, respectively.

In various other embodiments, device 800 may include a sheath (notshown) or similar mechanism configured to be placed over expandablemember 900 to retain, in a collapsed state, support members 920 made ofshaped-material. The sheath may be retracted to expose expandable member900, thereby allowing support members 920 to spring outwards so as toexpand surface 910 into a desired shape.

Support members 920 may be configured to provide expandable member 900with a suitable cross-sectional shape (e.g., circular, elongated, etc.)for accommodating the specific anatomy of the compartment 100 withinwhich device 800 will be deployed, for applying tension to fibrous wall110 of the compartment 100, and or for manipulating the position of, orminimizing pressure applied to, anatomical structures 120 situatedwithin compartment 100, as previously described.

Methods for Percutaneous Division of Fibrous Structures

FIGS. 11A-11C illustrate methods for percutaneous division of a fibrouswall 110 of an anatomical compartment 100 using various embodiments ofdevice 200.

Referring first to FIG. 11A, device 200, with balloon 400 in a deflatedstate, may be inserted into the body and advanced into anatomicalcompartment 100. Device 200 may be navigated into a position proximatefibrous wall 110, and oriented such that cutting element 500 is pointedtowards fibrous wall 110 and away from other critical structures, suchas anatomical structures 120. The positioning and orientation of cuttingelement 500, at this stage, may be confirmed by inspection, lightingelements 700, an imaging modality, a sensing/stimulating functionality600, or in other suitable manner, as previously described.

Referring now to FIGS. 11B and 11C, after confirming that cuttingelement 500 is properly positioned and oriented, a fluid such as salineor a contrast material may be directed through inflation lumen 340 ofcatheter 300 and into interior portion 410 of balloon 400 to inflateballoon 400.

In embodiments of device 200 comprising mechanical cutting element 510(as shown), inflation may continue until building pressure withinballoon 400 causes mechanical cutting element to engage fibrous wall 110with suitable force to weaken and thereby divide fibrous wall 110 underthe simultaneously-building tension provided by balloon 400.

In embodiments comprising electrical and/or thermal cutting elements 520(not shown), balloon 400 may first be inflated to a pressure sufficientto tension fibrous wall 110 to a desired level, at which point cuttingelements 520 may then be energized to weaken fibrous wall 110 andthereby divide it under the tension provided by balloon 400.

In various embodiments, the position and orientation of cutting edge 500may be rechecked throughout the inflation process. In one suchembodiment, balloon 400 may be partially inflated to a first pressuresuitable to give it some shape, at which point a recheck of position andorientation is performed before continuing. This may be repeated anynumber of suitable times during the inflation process to ensure thatfibrous wall 110 is divided properly, and without causing damage toanatomical structures 120.

Complete division of fibrous wall 110, in various embodiments, may beconfirmed by inspection, lighting elements 700 (as previouslydescribed), an imaging modality, or some other suitable technique (e.g.measuring a corresponding reduction in balloon pressure associated withdividing fibrous wall 110 and relieving the pressure within anatomicalcompartment 100).

Of course, one of ordinary skill in the art will recognize thatembodiments of device 800 may be utilized to divide fibrous wall 110 ina similar fashion. In various embodiments, rather than inflatingexpandable member 400 with fluid to tension fibrous wall 110 (and, ifequipped, engage fibrous wall 110 with mechanical cutting element 510 toweaken it), expandable member 900 of device 800 may be expandedmechanically, as previously described. As with device 200, expansion ofexpandable member 900 may be performed in a controlled manner so as toprovide intermediate opportunities to recheck the positioning andorientation of cutting element 500 relative to fibrous wall 110 andanatomical structures 120 so as to ensure that fibrous wall 110 isdivided properly and without causing collateral damage.

Methods for Treatment of Carpal Tunnel Syndrome

Embodiments of devices 200, 800 may be particularly well-suited fortreating carpal tunnel syndrome by dividing the transverse carpalligament. Referring to FIGS. 12A and 12B, the carpal tunnel is ananatomic compartment in the wrist bounded by the carpal bones and thetransverse carpal ligament. The clinical symptoms of carpal tunnelsyndrome primarily arise from compression of the median nerve as itpasses through the tunnel. Surgical division of the transverse carpalligament relieves the compression of the median nerve and its associatedsymptoms. Embodiments of devices 200, 800 are capable of dividing thetransverse carpal ligament percutaneously. In addition, expandablemembers 400, 900 may, in operation, dissect and mobilize the mediannerve and tendons away from the transverse carpal ligament, therebyenhancing the decompression of the carpal tunnel and potentiallypreventing late scarring and recurrent symptoms. For ease ofexplanation, the following methods for treatment of carpal tunnelsyndrome will be explained in the context of using device 200, though itshould be recognized that similar methods may be employed using device800 within the scope of the present disclosure.

Referring now to FIG. 12C, device 200, with balloon 400 in a deflatedstate, may be inserted into the body and advanced into the carpaltunnel. Device 200 may be navigated into a position proximate thetransverse carpal ligament, and oriented such that cutting element 500(shown here as an electrical and/or thermal cutting element 520) ispointed towards the transverse carpal ligament and away from othercritical structures, such as the median nerve and surrounding flexortendons. Embodiments of device 200 may be of suitable dimensions forpositioning within the carpal tunnel in proximity to the transversecarpal ligament. The positioning and orientation of cutting element 500,at this stage, may be confirmed by inspection, lighting elements 700, animaging modality, a sensing/stimulating functionality 600, or in othersuitable manner, as previously described.

Referring now to FIG. 12D, after confirming that cutting element 500 isproperly positioned and oriented relative to the transverse carpalligament and surrounding anatomical structures such as the median nerveand flexor tendons, balloon 400 may be inflated. Expandable member 400may be configured to expand to dimensions appropriate for use within thecarpal tunnel. Embodiments of balloon 400 having an elongatedcross-sectional shape, or other suitable shape, may act to dissect thetransverse carpal ligament off the carpal tunnel contents duringinflation, creating space and enhancing the decompression of the carpaltunnel. In such an embodiment, balloon 400 can be made of asubstantially noncompliant material and may be inflated to a specifiedpressure, designed to achieve this dissecting effect and to provideenough radial force to stretch the transverse carpal ligament acrosscutting element 500 for subsequent division. As shown in FIG. 12D, theinflated balloon 400 has dissected and pushed the median nerve and someof the flexor tendons away from one another, and away from cuttingelement 500. The inflated balloon 400 has also applied sufficienttension to the transverse carpal ligament such that it is stretched tautacross cutting element 500.

Referring now to FIG. 12E, cutting element 500 may be energized (orfurther pressure applied, in embodiments comprising mechanical cuttingelements 510) to weaken the contacted portion of the transverse carpalligament. Any of the described cutting elements 500 may be used for thisapplication. The unipolar or bipolar electrocautery leads 520 may beparticularly suitable for cutting the transverse carpal ligament, andbipolar embodiments may be preferred to protect the median nerve and itsbranches from injury. Once balloon 400 is inflated to a desiredpressure, cutting elements 520 may be energized to weaken a contactedportion of the transverse carpal ligament such that it may be divided incombination with the tension applied by balloon 400, as shown in FIG.12F.

In various embodiments, the position and orientation of cutting edge 500may be rechecked throughout the inflation process. In one suchembodiment, balloon 400 may be partially inflated to a first pressuresuitable to give it some shape, at which point a recheck of position andorientation is performed before continuing. This may be repeated anynumber of suitable times during the inflation process to ensure that thetransverse carpal tunnel is divided properly, and without causing damageto the median nerve and flexor tendons within the carpal tunnel.

Complete division of the transverse carpal ligament, in variousembodiments, may be confirmed by inspection, lighting elements 700 (aspreviously described), an imaging modality, or some other suitabletechnique (e.g. measuring a corresponding reduction in balloon pressureassociated with dividing the transverse carpal ligament and relievingthe pressure within the carpal tunnel).

Referring now to FIG. 13, in an embodiment, a kit 1000 may be providedalong with device 200 to facilitate introduction of the device 200 intothe carpal tunnel. Kit 1000, in various embodiments, may include animaging modality 1010, such as an ultrasound probe, a needle 1020, and aguidewire 1030. Kit 1000 may also include various dilators, guides orcatheters, as well as disposables such as sheath for the ultrasoundprobe (not shown).

The method of using the device to divide the transverse carpal ligamentcan be consistent with the general method. Although the procedure may beguided by direct inspection, lighting elements 700 or other technique,ultrasound guidance may be particularly useful. Ultrasound of the wristis a well-established technique which can clearly delineate thetransverse carpal ligament and its association with the median nerve. Itis routinely used to direct injections in the vicinity of the mediannerve to relieve symptoms of carpal tunnel syndrome.

With reference now to FIGS. 14A-14I, there is provided a method of useof device 200 to treat carpal tunnel syndrome using ultrasound guidance.The forearm and hand (FIG. 14A) are sterilely prepped and draped withthe hand in the hyperextended position. Local, regional or generalanesthesia may be instituted. A tourniquet may be used but is notnecessary. Anatomic landmarks are marked on the skin using palpation andultrasound imaging of the wrist. The proximal and distal edges of thetransverse carpal ligament can be identified as is the path of thepalmaris longus tendon. The path of the median nerve is followed as itpasses into and out of the carpal tunnel deep to the transverse carpalligament. Any anatomic anomalies (e.g. bifid median nerve) or otherpathology is identified. Measurements can be taken using ultrasound orother modalities including determining the width of the transversecarpal ligament. This allows the operator to select the appropriate sizekit instruments and cutting balloon catheter.

A skin entry site can be identified in the distal forearm severalcentimeters proximal to the proximal edge of the transverse carpalligament. The entry site is generally on the ulnar side of the parlmarislongus tendon and hence the median nerve providing a flat, straighttrajectory to the proximal edge of the transverse carpal ligament. Ofcourse, alternatively, the skin entry point may be in the hand with thedevice passing through the carpal tunnel from distal to proximal. Thedevice may also be designed to penetrate the carpal tunnel from a medialor lateral direction with the balloon inflating along the long axis ofthe tunnel although this approach introduces several additionalchallenges such as maneuvering around the radial and ulnar arteries.

Needle 1020 is inserted, as shown in FIG. 14B, at the skin entry siteand advanced from proximal to distal until it passes into the carpaltunnel just deep to the transverse carpal ligament. Ultrasound imagingcan be used to confirm that the tip of needle 1020 enters the carpaltunnel in the correct location, on the ulnar side of median nerve.Needle 1020 can be used to inject fluid or local anesthetic into thecarpal tunnel, if desired. This injection can be used to dissect tissuesaway from each other and create working space.

Guidewire 1030 is then inserted, as shown in FIG. 14C, into needle 1020and advanced through the carpal tunnel along a trajectory that runs justdeep to the transverse carpal tunnel and, again, ulnar to the mediannerve. Guidewire 1030 generally has a straight tip and is stiff enoughthat it can penetrate through the tissues bluntly. The tip of guidewire1030 can be tracked by ultrasound as it passes through the carpal tunneland exits past the distal edge of the transverse carpal ligament. At aminimum guidewire 1030 should pass a few centimeters past this edge toprovide an adequate rail for the balloon catheter. Ideally, guidewire1030 will be advance further so that it exits through the skin of thepalmar surface of the hand between the thenar and hypothenar eminences.This can be done under ultrasound guidance to assure that it exitscleanly and avoid critical hand structures such the arterial palmerarch. Once the tip of guidewire 1030 tents the skin of the hand, a smallnick in the skin with a knife blade will allow it to exit.Alternatively, needle 1020 can be advanced over guidewire 1030 so thatit penetrates the skin in the hand. Having a guidewire 1030 that exitsthe skin provides excellent column strength to facilitate positioning ofdevice 200. Needle 1020 can thereafter be removed, as shown in FIG. 14D.

An appropriately sized device 200 is then selected and advanced overguidewire 1030 into the carpal tunnel, as shown in FIG. 14E. Device 200can then be carefully positioned to ensure that its axial orientation iscorrect, with cutting element 500 positioned superficially, just underthe transverse carpal ligament. Its longitudinal position can beadjusted so that cutting element 500 spans the entire width of theligament. This positioning can be confirmed using ultrasound guidance.If the device contains lighting elements 700 previously described, thesecan be activated to confirm that cutting element 500 fully straddles theligament.

Once device 200 is properly positioned, balloon 400 may be inflated to aspecified pressure with fluid, as shown in FIG. 14F. The fluid can beany liquid including saline or contrast material including echo contrastmaterial or gas including air, carbon dioxide or oxygen. Ballooninflation can be monitored by direct inspection and palpation of thehand or by ultrasound guidance. The operator confirms that balloon 400inflates uniformly while maintaining its axial orientation anddissecting the transverse carpal ligament from the deeper structuresincluding the median nerve. If device 200 has the lighting element 700functionality, this can be used to reconfirm balloon position. If theposition is not optimal, balloon 400 can be deflated and the device 200repositioned before reinflating.

If device 200 has sensing and/or stimulating functionality (e.g.,elements 600), these can now be used to confirm that cutting element 500is not positioned too close to the median nerve, its branches or othernerves. The elements 600 may be connected to a signal detector and/orstimulator, respectively, as shown back in FIGS. 7A-7C. If these leads600 are on the same (superficial) surface of balloon 400 as cuttingelement 500, they are used to confirm the absence of nearbyneuroelectrical activity. If they are located on the opposite (deep)surface of balloon 400, they are used to confirm that the median nerveis away from cutting element 500 by sensing its signal or stimulatingit.

Once the position of cutting element 500 relative to the transversecarpal ligament and median nerve is confirmed, cutting element 500 isactivated, as shown in FIG. 14G. If cutting element 500 is anelectrocautery lead 520, it is connected to a radiofrequency generator.The generator is activated delivering radiofrequency energy to the lead520 as it cuts through the ligament. The cutting process can bemonitored by ultrasound and/or the lighting elements 700, if present.

Once the cutting process is terminated, balloon 400 is deflated and thecompleteness of the division of the transverse carpal ligament isconfirmed by ultrasound or other means, as shown in FIG. 14H. Device 200and guidewire 1030 can be removed, as shown in FIG. 14I. Additionallocal anesthesia can be infiltrated into the wrist. Sterile dressingsare applied. Appropriate post-operative care is instituted.

While the present disclosure has been described with reference tocertain embodiments thereof, it should be understood by those skilled inthe art that various changes may be made and equivalents may besubstituted without departing from the true spirit and scope of thedisclosure. In addition, many modifications may be made to adapt to aparticular situation, indication, material and composition of matter,process step or steps, without departing from the spirit and scope ofthe present disclosure. All such modifications are intended to be withinthe scope of the claims appended hereto.

What is claimed is:
 1. A method for dividing a fibrous structure, themethod comprising: positioning, proximate the fibrous structure, anexpandable member having a cutting element situated thereon; expandingthe expandable member outwards to tension the fibrous structure acrossthe cutting element; and activating the cutting element to weaken or cutthe fibrous structure.
 2. A method for dividing a fibrous structure asset forth in claim 1, wherein the expandable member is a balloon.
 3. Amethod for dividing a fibrous structure as set forth in claim 1, whereinthe cutting element is a blade.
 4. A method for dividing a fibrousstructure as set forth in claim 1, wherein the cutting element includesa unipolar lead or bipolar leads.
 5. A method for dividing a fibrousstructure as set forth in claim 1, wherein the cutting element is anelectrocautery lead.
 6. A method for dividing a fibrous structure as setforth in claim 5, wherein the step of activating the cutting elementincludes delivering radiofrequency energy to the electrocautery lead. 7.A method for dividing a fibrous structure as set forth in claim 3,wherein the step of activating the cutting element includes expandingthe expandable member to press the blade against the fibrous structure.8. A method for dividing a fibrous structure as set forth in claim 1,wherein the step of expanding the expandable member further serves tomanipulate a position of an anatomical structure located near theexpandable member.
 9. A method for dividing a fibrous structure as setforth in claim 1, further comprising the step of providing at least oneelement configured for sensing, stimulating, or both sensing andstimulating neuroelectrical activity.
 10. A method for dividing afibrous structure as set forth in claim 9, wherein the at least oneelement is situated on a surface of the expandable member.
 11. A methodfor dividing a fibrous structure as set forth in claim 9, furthercomprising the step of determining whether a nerve is present in thevicinity of the at least one element, comprising at least one of:monitoring feedback from the at least one element for signals associatedwith neurological activity; and emitting, via the at least one element,a signal suitable for stimulating neuroelectrical activity.
 12. A methodfor dividing a fibrous structure as set forth in claim 11, furthercomprising the step of adjusting a position, an orientation, or both aposition and an orientation of the cutting element responsive todetecting the presence of a nerve in a vicinity of the sensing orstimulating element.
 13. A method for dividing a fibrous structure asset forth in claim 9, wherein the at least one element is a sensingelement or an element configured for both sensing and stimulatingneuroelectrical activity.
 14. A method for dividing a fibrous structureas set forth in claim 13, wherein the step of determining whether anerve is present in the vicinity of the at least one element includesmonitoring feedback, from the sensing element or element configured forboth sensing and stimulating neuroelectrical activity, to detect anelectrical signal emanating from the nerve at baseline, from activationof motor nerve fibers during normal muscle contraction, or duringelectrical stimulation of the nerve.
 15. A method for dividing a fibrousstructure as set forth in claim 9, wherein the at least one element is astimulating element or an element configured for both sensing andstimulating neuroelectrical activity.
 16. A method for dividing afibrous structure as set forth in claim 15, wherein the step ofdetermining whether a nerve is present in the vicinity of the at leastone element includes emitting, from the stimulating element or elementconfigured for both sensing and stimulating neuroelectrical activity, anelectrical stimulus and motoring the body for a corresponding motorreaction.